Hygroscopicity of baru (Dipteryx alata Vogel) fruit

Abstract

A B S T R A C TWith the knowledge on the hygroscopic equilibrium of the baru (Dipteryx alata Vogel) fruit, the product can be adequately handled to maintain the moisture content at the levels recommended for safe storage. Thus, this paper aimed to determine the water desorption isotherms of baru fruits at temperatures of 20, 25, 30 and 35 °C, and water activity between 0.14 and 0.80, and obtain the values of isosteric heat of desorption as a function of the equilibrium moisture content of the product. The equilibrium moisture content was obtained using the static-gravimetric method. Modified Halsey was the best model recommended to represent the hygroscopicity of baru fruits. The recommended moisture contents for safe storage of baru fruits are not more than 19.9, 19.3, 18.6 and 18.0 (%, d.b.) for the respective temperatures of 20, 25, 30 and 35 °C. The integral isosteric heat of desorption increases as the water content decreases, leading to an increment in the energy required to remove water from the product.Higroscopicidade dos frutos de baru (Dipteryx alata Vogel) R E S U M OCom o conhecimento do equilíbrio higroscópico dos frutos de baru (Dipteryx alata Vogel), pode-se manejar adequadamente o produto visando à manutenção de seu teor de água nos níveis recomendados para o armazenamento seguro. Desta forma, objetivou-se determinar as isotermas de dessorção de água dos frutos de baru nas temperaturas de 20, 25, 30, 35 °C e atividades de água entre 0,14 e 0,80 e obter os valores do calor isostérico de dessorção em função do teor de água de equilíbrio do produto. Para obtenção do teor de água de equilíbrio foi utilizado o método estático-gravimétrico. O modelo de Halsey Modificado foi o melhor modelo recomendado para representar a higroscopicidade dos frutos de baru, cujos teores de água recomendados para o armazenamento seguro dos frutos de baru são de, no máximo, 19,9; 19,3; 18,6 e 18,0 (% b.s), para as respectivas temperaturas de 20, 25, 30 e 35 °C. O calor isostérico integral de dessorção aumenta com a redução do teor de água ocorrendo incremento da energia necessária para a remoção de água do produto.

Composition and physicochemical properties of dried berry pomace

“…The WBC of fruits is mainly determined by sugar content and surface characteristics, with convective drying resulting in minor porosity and hygroscopicity compared to other drying methods . Compared to other fruits and their by‐products, powders from berry pomace adsorb less moisture at 20/25 °C as a result of processing and compositional properties . Regarding the presumptive applications of dried berry pomace as a food ingredient, a wide range of food systems is possible, particularly sweet or savoury baked products.…”

“…63 Compared to other fruits and their by-products, powders from berry pomace adsorb less moisture at 20/25 ∘ C as a result of processing and compositional properties. 62,64,65 Regarding the presumptive applications of dried berry pomace as a food ingredient, a wide range of food systems is possible, particularly sweet or savoury baked products. Depending on berry variety and substitution level, the powders will have an impact on colour, rheological properties, texture and nutritional value.…”

Mechanical properties of saccharine sorghum (Sorghum bicolor L. Moench) seeds

“…Seeds with higher moisture contents are less resistant to compression; compression increases proportionally with the decrease in moisture content and the increase in deformation (Oliveira et al, 2017). According to Gupta & Das (2000), this tendency may be owing to a gradual change in the cell matrix integrity with the reduction in moisture content.…”

“…The reduction in moisture content resulted in a linear increase in the force necessary to achieve the "bioyield point" of the range 78.78-53.10 N. This point represents the beginning of the seed's rupture. Oliveira et al (2017) reported that such a behavior may be related to a higher cellular density that occurred with water leakage during drying, i.e., number of cells per unit volume increased, thus resulting in a greater resistance to compression at lower moisture contents. Our results were in agreement with those obtained for other agricultural products, including Cuminum cyminum Linn.…”

“…Our results were in agreement with those obtained for other agricultural products, including Cuminum cyminum Linn. seeds (Saiedirad et al, 2008), sunflower seeds (Sharma et al, 2009), rough rice (Resende et al, 2013), and baru fruits (Oliveira et al, 2017).…”